According to the investigation, the players regularly contributed cash into a pool and received improper cash payments of two kinds from the pool, based on their play in the previous week’s game.

Williams administered the program with the knowledge of other defensive coaches and occasionally contributed funds, according to the league investigation.

Payments were made for plays such as interceptions and fumble recoveries. But the program also included “bounty” payments for “cart-offs,” meaning that the opposing player was carried off the field, and “knockouts,” meaning that the opposing player was not able to return.

The investigation showed that the total amount of funds in the pool may have reached $50,000 or more at its height during the 2009 playoffs. The program paid players $1,500 for a “knockout” and $1,000 for a “cart-off,” with payouts doubling or tripling during the playoffs.

“The payments here are particularly troubling because they involved not just payments for ‘performance,’ but also for injuring opposing players,” Goodell said in a statement. “The bounty rule promotes two key elements of NFL football: player safety and competitive integrity.”